The link between thought and performance on a test, stage or in sports has been shown in many studies. Think positively and repeat phrases like "I can do it", and you're likely to do better.

But a new study breaks down various types of motivational thinking, referred to as self-talk, for various types of sports. And it finds that different kinds of motivation have different effects.

Researchers analyzed the use of self-talk in 32 sports-related psychology studies. And they found that, for fine motor skills like improving your swimming stroke, instructional self-talk works best, as in repeating specific phrases like "elbow-up" in our head. This kind of specific reminder is a lot more effective in these cases than are general motivational statements like "Give it your all."

The researchers found that self-talk has its greatest positive impact on tasks that require concentration, like sinking the eight ball, as opposed to endurance events like running, where putting your best foot forward may be less important than simply taking another step.